The association between long-term fine particulate air pollution and life expectancy in China, 2013 to 2017

China is experiencing one of the worst air quality problems in the world. China implemented the Air Pollution Prevention and Control Action Plan (APPCAP) and the air quality has recently achieved remarkable improvement.To evaluate the associations of variations in annual fine particulate matter (PM2.5) levels and changes in life expectancy in Chinese urban populations from 2013 to 2017.We collected annual-average concentrations of PM2.5 and average life expectancy of urban residents in 214 cities from 2013 to 2017. We conducted a longitudinal panel analysis applying linear mixed-effect models to evaluate the association between PM2.5 reduction and life expectancy increase with and without adjustment for socioeconomic and medical-care confounders.The nationwide-average annual PM2.5 concentrations decreased from 67.78 μg/m3 in 2013 to 45.25 μg/m3 in 2017; meanwhile, the average life expectancy of urban residents increased from 78.53 to 79.86 years. A decrease of 10 μg/m3 in PM2.5 was associated with an increment of 0.18 (95% confidence interval: 0.06, 0.30) year in life expectancy. After simultaneously adjusting for GDP per capita, smoking prevalence, urbanization rate and maternal mortality, the association turned to be insignificant at the national level, but remained significant in the eastern region with life expectancy gained 0.16 (95% CI: 0.04, 0.27) year per 10 μg/m3 reduction of PM2.5.Lower PM2.5 air pollution might be associated with extended life expectancy in east of China. The implementation of APPCAP during 2013 to 2017 might have resulted in benefits on life expectancy, especially in east of China.